Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Latgalian
ar
←
Proto-Indo-European
*h₂er-
(derived)
←
Lithuanian
ar
(cognate)
←
Latvian
ar
(cognate)